When Roche left its sprawling campus in northern New Jersey two years ago, it was part of a broader challenge for the state—filling the cavernous centers that once housed the booming pharmaceutical industry.

On Thursday, officials at Seton Hall University and Hackensack University Medical Center plan to announce they want to fill some of that space with a new medical school, the state’s only private one, which they hope to open in 2017.

It would be welcome news for Nutley and neighboring Clifton, which were slammed in 2012 when Roche left, taking more than 1,000 jobs.

“It will help address the needs of the state and the needs of the nation,” said
Robert Garrett,
chief executive of Hackensack University Medical Center. “There will be a physician shortage in New Jersey that becomes even more acute over the next few years.”

Gov.
Chris Christie
is expected to attend the announcement, which will be held at the Nutley campus. The drug industry’s shrinking footprint in New Jersey has left towns like Nutley struggling to fill tax gaps and attract companies to ghost towns of office parks and has played a part in the state’s economic challenges.

New Jersey has shed thousands of pharmaceutical jobs over the past two decades, said
James Hughes,
dean of the public planning and policy school at Rutgers University. He said the state once had about 20% of the country’s pharmaceutical jobs but now has about 10%.

About 100 acres will remain unoccupied at the campus, but town officials are likely to have better luck with the prospect of a medical school occupying part of it, say economic development officials.

“It was a big, huge deal when they left,” said
Luther Engler,
who is on the board of Nutley’s Chamber of Commerce. “They paid millions in taxes, and every business in town felt it, from the restaurants to the delis to the shops.”

For the planned medical school, New Jersey’s bust could prove a boon. Laboratories where medicine was once created can be tweaked and used. Many of the facilities need little work because they are already “state-of-the art, pristine buildings,” said Mr. Garrett, the hospital’s chief executive.

Many questions remain about the school, which hopes to train 125 to 150 doctors a year. Planners say they want state incentives for the school, but a package hasn’t been determined. A state spokeswoman didn’t return a request for comment.

Officials haven’t fully worked out the financial model, tuition costs or fundraising plans, or the school’s leadership.

Seton Hall President
Gabriel Esteban
said the school would likely charge similar to what other schools charge for medical schools.

“My daughter is in medical school, and she pays $54,000 a year,” he said.

The school also would need accreditation from the Liaison Committee on Medical Education, which could take more than a year.

Components of the approval process include proving adequate financial resources, a need in the community and viable leaders, said
John Prescott,
chief academic officer for the Association of American Medical Colleges.

There are 141 accredited schools nationwide, Mr. Prescott said, with about 15 opening over the past decade.

New Jersey has four other medical schools, according to according to the New Jersey Council of Teaching Hospitals.

“The process is an arduous one, to say the least, and can be lengthy,” Mr. Prescott said. “Many start down the process and don’t complete it. It’s not for the fainthearted.”

Mr. Prescott and others said New Jersey and the country are likely to suffer from a deeper shortage of primary-care physicians, as the baby boomer population ages.

In New Jersey, medical schools often cater to—and attract—students who want to learn specialized medicine, said
Deborah Briggs,
chief executive of the state’s hospital teaching council.

Those jobs pay more and often allow more schedule flexibility. But New Jersey needs at least 1,000 more primary-care physicians, Ms. Briggs said, and she projects that number to balloon to 3,000 by 2020.

Mr. Garrett said much of the faculty would come from the hospital and the university, and that the institution will focus on training primary-care physicians.

With the competitive medical school process, Mr. Garrett said he expected it would be easy to find qualified students from New Jersey and across the country.

Seton Hall officials had considered a medical school since 2009, Mr. Esteban said, but began talking with Hackensack only in the past two years. It first considered opening a stand-alone institution but the partnership made more sense, he said.

“Being in higher ed, the fact that we started where we are in 2009 and where we are today, that’s a fairly orderly and great fashion. It’s not like in the private sector where things are done overnight,” he said.